The invention relates to a method for producing filter elements in the tobacco-processing industry, in particular multi-segment filters consisting of a first filter segment and at least one second filter segment. The invention furthermore relates to a filter, in particular a multi-segment filter, as well as an apparatus for producing filter elements in the tobacco-processing industry and in particular for producing multi-segment filters having a first filter segment and at least one second filter segment. The invention also relates to a machine for producing filters in the tobacco-processing industry, in particular multi-segment filters.
U.S. Pat. No. 5,088,507 discloses an apparatus for joining an aerosol-generating cartridge and a completed filter cigarette, wherein the cartridge is inserted into the cigarette and a support tube is ejected following the completion.
However, this apparatus is not suitable for producing filter segments for a multi-segment filter since only the final products are joined in the disclosed apparatus. Among other things, multi-segment filters consist of fragile, impact-sensitive filter sections, wherein the filter sections are not surrounded by an enveloping paper strip, but are combined to form a group of filter segments which are subsequently shaped into a filter rope with the aid of a rope-forming technique.
For the production of cigarette filters, in particular multi-segment filters, the filter rods are produced from different types of basic filter rods, in accordance with the desired filter characteristics. The basic filter rods are cut for this, are grouped together, enveloped inside a filter-rod producing machine and are then cut into multiple-length filter rods.
Among other things, hard filter elements are also used for producing multi-segment filters. Since hard filter elements consist either of an impact-sensitive and breakable material or of a non-elastic and non-compressible hard material, it is important that the sensitive hard elements be handled and conveyed with extreme care during the filter production.